Gas turbine engines, such as those utilized in military and commercial aircraft utilize a compressor portion to compress air, a combustor portion to mix the compressed air with a fuel and ignite the mixture, and a turbine portion to expand the resultant gasses from the ignition. The expansion of the gasses in the turbine section drives the turbine section to rotate. The turbine section is tied to the compressor section by at least one shaft, and the rotation of the turbine section drives the rotation of the compressor section.
Included in the compressor section and the turbine section are multiple rotors. Each of the rotors includes a radially inward rotor disk and multiple rotor blades protruding radially outward from the rotor disk. The rotor blades are airfoil blades that protrude into the flow path defined by the compressor section and the turbine section. The rotor disks, and particularly the radially inward portions of the rotor disks, are thicker and take longer to heat up and cool down than the radially outward portion of the disks and the blades extending from the disks. As a result, thermal gradients can occur across the rotor disk. The thermal gradients reduce the effective lifespan of the disk.